(from page 12 of the 1973 Collection)
The 1973 Mustang, Q-code, 266hp (at 5400rpm), 351 cubic inch, 4 barrel, Cobra Jet V8 engine. This is the one of the two most powerful engine options offered in 1973.

(from page 17 of the 1973 Collection)
The engine is a Q-code 351ci Cobra Jet V8. It is bored 3 over which a 750cfm Edelbrock carb and matching intake.